Design method of input phase mask to improve light use efficiency and reconstructed image quality for holographic memory

Abstract

A design method of an input phase mask for holographic memory is proposed. In the method, a modification of a design procedure and another restraint condition are applied to our conventional design method. The light use efficiency and the quality of a reconstructed image are improved. The performance of an input phase mask designed by the method is confirmed by numerical simulations. Finally, a suitable design condition of an input phase mask is determined from simulation results.

Recording procedures for high-quality signal readout in self-referential holographic data storage

“…This means that the peak of the intensity that causes the concentration of the elemental holograms is undesirable in SR-HDS. Although we used the binary additional pattern with a phase shift of π in this study, it is expected that further improvement of the SNR will result from designing additional patterns appropriately, as has been recently studied for the two-wave and collinear HDS systems [8,17,20].…”

“…In particular, holographic data storage (HDS), in which digital data are recorded in hologram form, is one of the post-Blu-ray disc (BD) technologies with the potential for high recording density and fast data access [1][2][3][4]. Although the data density and the data access rate of HDS have been drastically improved by recent vigorous studies [5][6][7][8], the fundamental optical geometry has remained nearly unchanged since its invention in 1963 [9]. Since HDS usually requires two mutually coherent beams, generally referred to as the signal and reference beams, its optical system will become larger than and/or more complex than the conventional optical data storage systems.…”

Linear phase encoding for holographic data storage with a single phase-only spatial light modulator

“…(6). This equation shows that each spectrum H n is separately distributed owing to the spatial carrier frequencies f x and f y .…”

“…In the case that the recording medium is set on the Fourier plane of a lens, a high-intensity zero-order beam deteriorates the interference efficiency and wastes the dynamic range of a recording medium. In general, to solve this problem, the phase distribution of the signal beam is modulated with a random phase mask [3,4] or a phase-only SLM [5,6]. This makes the Fourier power spectrum of a signal beam have a uniform distribution, and thus the quality of reconstructed data can be improved.…”

Diffractive Deep-Neural-Network-Based Classifier for Holographic Memory

“…Data pages are typically represented as amplitude-only data. To reduce the consumption of holographic media [1], phase-only data have been used [6,7]. Complex amplitude data pages have been proposed [8][9][10][11].…”